FIG. 1 shows a schematic diagram of a common 2D and 3D image switchable display. The common 2D and 3D image switchable display 10 comprises a liquid crystal view separator 12, usually, which is installed in front of a screen of a liquid crystal display 11. For a view position of a viewer 13, an installation method for installing the liquid crystal view separator 12 in front of the screen of the liquid crystal display 11 is hereinafter referred to as a front installation method for short.
Besides, under the driving of an external appropriate electrical voltage V, the liquid crystal view separator 12 may present a transparent light penetration state to achieve an effect of 2D image display, or present a view separation state to achieve an effect of 3D image display.
Generally, the liquid crystal view separator 12 may consist of a liquid crystal lenticular device or a liquid crystal parallax barrier device. The related art of the present disclosure belongs to the field of liquid crystal lenticular devices, in particular to the field of technologies of using a surface relief method to achieve the aim of 2D and 3D switchable display. The prior art is only illustrated herein below for a common surface relief method liquid crystal lenticular device.
FIG. 2 shows a composition schematic diagram of a surface relief liquid crystal lenticular device. The structure shown in FIG. 2 is disclosed in American Patent U.S. Pat. No. 6,069,650 and described with reference to FIG. 3 in the description.
The surface relief liquid crystal lenticular device 15 mainly includes a conventional lenticular sheet 30, two ITO electrode layers 34, 37, an electro-optic material 38 with an electrically changeable refractive index, and a transparent planar substrate 36. The conventional lenticular sheet 30 consists of several parallel lenticular modules 16, and each parallel lenticular module 16 consists of convex lenses optically, is made of transparent polymeric materials, and can be generated by molding, machining or photolithographic process. The transparent planar substrate 36 consists of flat transparent glass or plastic materials. The two ITO electrode layers 34, 37 respectively cover a surface 32 of the parallel lenticular module 16 and a surface 34 of the transparent planar substrate 36. Space between the two surfaces is full of the electro-optic material 38 with an electrically changeable refractive index. The electro-optic material 38 with an electrically changeable refractive index may be liquid crystal material, and generally, may be nematic liquid crystal material.
A technology of the surface relief liquid crystal lenticular device 15 disclosed in the patent U.S. Pat. No. 6,069,650 only pertains to theoretical structure formation, and does not meet requirements of a common liquid crystal technology. For example, the ITO electrode layer 34 is arranged on an arc surface of a lenticular lens, a uniformly-distributed parallel electric field cannot be formed between the ITO electrode layer 34 and the ITO electrode layer 37. Finally, liquid crystal molecules cannot be arranged in the same direction.
FIG. 3 shows a composition schematic diagram of an improved surface relief based liquid crystal lenticular device. The structure shown in FIG. 3 is disclosed in American Patent US20080259233 and described with reference to FIG. 2 and FIG. 3 in the description.
The surface relief based liquid crystal lenticular device 50 is improved for the defects of the patent U.S. Pat. No. 6,069,650. Namely, an ITO electrode is moved from an arc surface of a lens to a plane. The surface relief based liquid crystal lenticular device 50 mainly includes upper and lower transparent substrates 39, 41, upper and lower ITO electrode layers 43, 45, a plano-concave lens module 47, and a plurality of liquid crystal molecules 49. The plano-concave lens module 47 has a refractive index np; and the liquid crystal molecules 49 may be nematic liquid crystal materials, and have the characteristics of birefringent optics in which an ordinary refractive index is no and an extraordinary refractive index is ne, where no=np, and ne>np. The upper and lower ITO electrode layers 43, 45 are connected to a power supply V.
Besides, the surface relief based liquid crystal lenticular device 50 is installed in front of a liquid crystal screen (unmarked in the figure), which is used to display a 2D or 3D image (unmarked in the figure). After passing through a polarizer on the outermost layer of the liquid crystal screen, a light source of the 2D or 3D image becomes a light source 53 for linear polarization, and a polarization direction thereof vertical to a paper surface.
Without an additional electric field, namely V=OFF, arrangement of the nematic liquid crystal molecules 49 has the characteristics that an optical axis is vertical to the paper surface. For an incident light 53, the extraordinary refractive index ne is sensed because that the light polarization direction is parallel to the optical axes of the liquid crystal molecules 49. Besides, when the incident light 53 penetrates through the plano-concave lens module 47, due to ne>np, the incident light 53 is effected by a convex lens, the abovementioned optical characteristics are applicable to display of a 3D image.
Besides, as shown in FIG. 4, under an additional electric field, namely V=ON, arrangement of the nematic liquid crystal molecules 49 has the characteristics that an optical axis is parallel to the paper surface and vertical to the upper and lower ITO electrode layers 43, 45, namely parallel to the direction of the electric field (unmarked in the figure). For an incident light 53, the ordinary refractive index no is sensed because the light polarization direction is vertical to the optical axes of the liquid crystal molecules 49. Besides, when the incident light 53 penetrates through the plano-concave lens module 47, due to no=np, the incident light 53 can directly penetrate through the plano-concave lens module 47 without any influence of the plano-concave lens module 47, and therefore the abovementioned optical characteristics are applicable to display of a 2D image.
A technology of the surface relief based liquid crystal lenticular device 50 disclosed in the patent US20080259233 pertains to theoretical structure formation, and does not meet requirements of a common liquid crystal cell technology. For example, the plano-concave lens module 47 and the lower ITO electrode layer 45 are not provided with an alignment film layer (1), a spacing layer (2), an electrically connected structure (3), a sealing plastic structure (4) or other structures. Finally, the surface relief based liquid crystal lenticular device 50 cannot form an module which is truly producible and usable.
In conclusion, the above three liquid crystal lenticular devices all have the characteristics of achieving the changeable refractive index by liquid crystal molecules. Therefore, the above common technologies can fall within the technical field of liquid crystal dependent liquid crystal lenticular devices.